Synthesis of 2-iminonitroxide-substituted phenols and pyridine-3-oles.
作者:Eugene V. Tretyakov、Ilia V. Eltsov、Sergey V. Fokin、Yurii G. Shvedenkov、Galina V. Romanenko、Victor I. Ovcharenko
DOI:10.1016/s0277-5387(03)00228-6
日期:2003.7
Methods for the synthesis of a new family of nitronylnitroxides, iminonitroxides, and their precursors with 2-hydroxyphenyl or 3-hydroxypyridin-2-yl substituents in the side chain have been developed. Five heterospin chelates of Cu(II) with deprotonated iminonitroxides have been isolated. Their structure and magnetic properties have been studied. In all complexes, ferromagnetic intramolecular exchange interactions take place (J similar to 40-350 cm(-1)) (C) 2003 Elsevier Science Ltd. All rights reserved.
Synthesis and magnetic properties of an iminonitroxide-substituted phenolate–Cu complex
A new spin-chelate, iminonitroxide-substituted phenolate-copper complex (1), was designed and prepared. The structure of the complex I was considerably deviated from a square-planar geometry. The dihedral angle between the two planes defined by a set of copper, oxygen and nitrogen atoms was about 41degrees. The complex was found to have a relatively strong ferromagnetic interaction and a weaker antiferromagnetic interaction: J/k(B) = +250 K and theta = -17 K using a three-spin model. The ferromagnetic interaction was assigned to the intramolecular interaction between the copper atom and the iminonitroxide. The antiferromagnetic interaction was assigned as an intermolecular interaction. These assignments were supported by susceptibility measurements for the diluted sample in polyvinyl chloride (PVC) film. The antiferromagnetic interaction was tentatively assigned due to the observed short intermolecular contacts between the C5 and 01 atoms or between the H5 and 01 atoms. (C) 2003 Elsevier Science Ltd. All rights reserved.